Details of the triple-0 call made by Dreamworld staff to emergency services moments after a ride malfunctioned, killing four people, have been revealed for the first time at an inquest into the deaths.

The deaths of Cindy Low, Kate Goodchild, Luke Dorsett and Roozi Araghi are under examination in a Queensland coronial inquest after the group were killed instantly when their raft collided with an empty vessel and flipped backwards in 2016.

A transcript of Mr Irwin's conversation with emergency services was displayed to the court on Tuesday afternoon.

"We have somebody trapped in the machinery," Mr Irwin said.

"Okay. So, there's two people?" the call taker replied.

"At least … The whole raft has emptied up into the water," Mr Irwin said.

"We may obviously need more than one [ambulance] I dare say."

The rest of the transcript was not shown to the inquest, due to concerns about distress it would cause family members of the victims.

Earlier, the inquest on the Gold Coast heard the ride was declared "mechanically and structurally safe" eight days before the accident.

The inquest was also shown photos of a similar incident that occurred 15 years earlier and a near-miss from 2014.

The court was also shown photos from an incident in 2001 when a number of empty rafts flipped over and were damaged, and CCTV footage of a 2014 near-miss, when two rafts with people in them ran into each other at the top of the conveyer belt.

No one was injured in the 2014 incident. However, ride operator Stephen Buss was sacked.

During questioning, Dreamworld junior engineer Gen Cruz said he was not made aware of either the 2001 or 2014 incident until after the 2016 tragedy.

Toby Nielsen, the barrister representing the Araghi family, suggested the theme park had a a "culture of secrecy" when there were incidents with rides.

He asked Mr Cruz if he agreed.

After a long pause, Mr Cruz softly replied "no".

Mr Cruz also said he believed he was the only engineer employed at Dreamworld in 2016, but he did not know whose responsibility it was to identify the cause of a problem after any incidents on a ride.